1/*
 2 * Stack trace utility
 3 *
 4 * Copyright 2008 Christoph Hellwig, IBM Corp.
 5 *
 6 *
 7 *      This program is free software; you can redistribute it and/or
 8 *      modify it under the terms of the GNU General Public License
 9 *      as published by the Free Software Foundation; either version
10 *      2 of the License, or (at your option) any later version.
11 */
12
13#include <linux/export.h>
14#include <linux/sched.h>
15#include <linux/sched/debug.h>
16#include <linux/stacktrace.h>
17#include <asm/ptrace.h>
18#include <asm/processor.h>
19
20/*
21 * Save stack-backtrace addresses into a stack_trace buffer.
22 */
23static void save_context_stack(struct stack_trace *trace, unsigned long sp,
24			struct task_struct *tsk, int savesched)
25{
26	for (;;) {
27		unsigned long *stack = (unsigned long *) sp;
28		unsigned long newsp, ip;
29
30		if (!validate_sp(sp, tsk, STACK_FRAME_OVERHEAD))
31			return;
32
33		newsp = stack[0];
34		ip = stack[STACK_FRAME_LR_SAVE];
35
36		if (savesched || !in_sched_functions(ip)) {
37			if (!trace->skip)
38				trace->entries[trace->nr_entries++] = ip;
39			else
40				trace->skip--;
41		}
42
43		if (trace->nr_entries >= trace->max_entries)
44			return;
45
46		sp = newsp;
47	}
48}
49
50void save_stack_trace(struct stack_trace *trace)
51{
52	unsigned long sp;
53
54	sp = current_stack_pointer();
55
56	save_context_stack(trace, sp, current, 1);
57}
58EXPORT_SYMBOL_GPL(save_stack_trace);
59
60void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
61{
62	unsigned long sp;
63
64	if (tsk == current)
65		sp = current_stack_pointer();
66	else
67		sp = tsk->thread.ksp;
68
69	save_context_stack(trace, sp, tsk, 0);
70}
71EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
72
73void
74save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace)
75{
76	save_context_stack(trace, regs->gpr[1], current, 0);
77}
78EXPORT_SYMBOL_GPL(save_stack_trace_regs);

 1/*
 2 * Stack trace utility
 3 *
 4 * Copyright 2008 Christoph Hellwig, IBM Corp.
 5 *
 6 *
 7 *      This program is free software; you can redistribute it and/or
 8 *      modify it under the terms of the GNU General Public License
 9 *      as published by the Free Software Foundation; either version
10 *      2 of the License, or (at your option) any later version.
11 */
12
13#include <linux/module.h>
14#include <linux/sched.h>
 
15#include <linux/stacktrace.h>
16#include <asm/ptrace.h>
17#include <asm/processor.h>
18
19/*
20 * Save stack-backtrace addresses into a stack_trace buffer.
21 */
22static void save_context_stack(struct stack_trace *trace, unsigned long sp,
23			struct task_struct *tsk, int savesched)
24{
25	for (;;) {
26		unsigned long *stack = (unsigned long *) sp;
27		unsigned long newsp, ip;
28
29		if (!validate_sp(sp, tsk, STACK_FRAME_OVERHEAD))
30			return;
31
32		newsp = stack[0];
33		ip = stack[STACK_FRAME_LR_SAVE];
34
35		if (savesched || !in_sched_functions(ip)) {
36			if (!trace->skip)
37				trace->entries[trace->nr_entries++] = ip;
38			else
39				trace->skip--;
40		}
41
42		if (trace->nr_entries >= trace->max_entries)
43			return;
44
45		sp = newsp;
46	}
47}
48
49void save_stack_trace(struct stack_trace *trace)
50{
51	unsigned long sp;
52
53	asm("mr %0,1" : "=r" (sp));
54
55	save_context_stack(trace, sp, current, 1);
56}
57EXPORT_SYMBOL_GPL(save_stack_trace);
58
59void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
60{
61	save_context_stack(trace, tsk->thread.ksp, tsk, 0);
 
 
 
 
 
 
 
62}
63EXPORT_SYMBOL_GPL(save_stack_trace_tsk);